Portions of a truck cab



FIG. 1 is a front right perspective view of portions of a truck cab showing our new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a front view thereof; and,

FIG. 5 is a back right perspective view thereof.

The broken lines of the figures showing additional portions of the truck are included for the purpose of illustrating environmental structure and form no part of the claimed design. 

The ornamental design for a portions of a truck cab, as shown and described. 